variation occurred between M. leidyi and the other three species
(t statistic).
The bacterial richness (alpha diversity) (Fig. S1, Supporting
Information), as estimated by the ARISA-OTU numbers, was
variable among all four species. The highest OTU richness was
recorded in Beroe sp. (S = 36), followed by B. infundibulum (S = 22)
and M. leidyi (S = 21), whereas the lowest richness was observed
in P. pileus (S = 5).